From 5b653ccffdc33c8774697a93cad0b499b88dca71 Mon Sep 17 00:00:00 2001 From: Charles Date: Sun, 28 Jul 2019 21:12:28 +0200 Subject: std library function almost done, tested with libft-unit-tests --- ft_atoi.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) create mode 100644 ft_atoi.c (limited to 'ft_atoi.c') diff --git a/ft_atoi.c b/ft_atoi.c new file mode 100644 index 0000000..94c42cc --- /dev/null +++ b/ft_atoi.c @@ -0,0 +1,33 @@ +#define MIN_INT (1 << 31) +#define MAX_INT (~(1 << 31)) + +int ft_atoi(const char *nptr) +{ + unsigned int nb; + int i; + int is_negative; + + while (*nptr == ' ' || *nptr == '\t'|| *nptr == '\n' + || *nptr == '\v'|| *nptr == '\f'|| *nptr == '\r') + nptr++; + is_negative = 0; + if (*nptr == '-' || *nptr == '+') + { + if (*nptr == '-') + is_negative = 1; + nptr++; + } + i = 0; + nb = 0; + while (nptr[i] >= '0' && nptr[i] <= '9') + { + if (!is_negative && nb > (unsigned int)MAX_INT) + return (-1); + else if (nb > (unsigned int)MIN_INT) + return (0); + nb *= 10; + nb += nptr[i] - '0'; + i++; + } + return ((int)(is_negative ? -nb : nb)); +} -- cgit